Rotary engine

ABSTRACT

A two-stroke cycle, internal combustion engine in which pairs of hollow pistons are fixedly mounted on opposite sides of a hollow stationary shaft, and radially arranged cylinders revolve about a crank pin on a rotary drive shaft, said shafts being aligned on a common axis. The cylinders also orbit in a circular path about said axis, and the speed and direction of rotational and orbital movement are synchronized by a stationary gear coaxial with said drive shaft and meshing with a ring gear that is centered with respect to the cylinders. There are twice as many cylinders as pistons, and each piston leaves one cylinder at the end of its power stroke and enters another cylinder 180* around from the first at the beginning of its next compression stroke. Fuel is injected into the combustion chambers through nozzles in the pistons. Spark plugs (if used) are mounted on the outer ends of the pistons. Fuel lines and ignition wires pass outwardly through the hollow stationary shaft. Air is blown through the stationary shaft and hollow pistons to cool the latter, and jets of air are blown into the cylinders as each piston enters the cylinder, to scavenge any remaining combustion gas.

United States Patent Shrewsbury et al.

[ 1 Aug. 22, 1972 ROTARY ENGINE [72] Inventors: Robert M. Shrewsbury,351 .3 Redlands Dr., Bakersfield, Calif. 93306; Jake J. Walcker, 286Merrywood Circle, Mira Loma, Calif. 91752 [22] Filed: March 24, 1971 [211 Appl. No.: 127,569

[52] US. Cl. ..l23/8.09, 123/845, 4l8/6l,

418/91, 4l8/99, 4l8/l5l, 4l8/l6l, 418/187 [51] Int. Cl. ..F02b 53/00,F03c 3/00 [58] Field of Search ..l23/8.09, 8.45',4l8/6l, l6], 4l8/9l,99,l5l, I87

5/1970 Rashev ..4l,8/ l X PrimaryExaminer-Allan D. HerrmannAttorney-Herbert E. Kidder [57] ABSTRACT A two-stroke cycle, internalcombustion engine in which pairs of hollow pistons are fixedly mountedon opposite sides of a hollow stationary shaft, and radially arrangedcylinders revolve about a crank pin on a rotary drive shaft, said shaftsbeing aligned on a common axis. The cylinders also orbit in a circularpath about said axis, and the speed and direction of rotational andorbital movement are synchronized by a stationary gear coaxial with saiddrive shaft and meshing with a ring gear that is centered with respectto the cylinders. There are twice as many cylinders as pistons, and eachpiston leaves one cylinder at the end of its power stroke and entersanother cylinder 180 around from the first at the beginning of its nextcompression stroke. Fuel is injected into the combustion chambersthrough nozzles in the pistons. Spark plugs (if used) are mounted on theouter ends of the pistons. Fuel lines and ignition wires pass outwardlythrough the hollow stationary shaft. Air is blown through the stationaryshaft and hollow pistons to cool the latter, and jets of air are blowninto the cylinders as each piston enters the cylinder, to scavenge anyremaining combustion gas.

10 Clains, 7 Drawing Figures ROTARY ENGINE BACKGROUND OF THE INVENTIONThis invention pertains generally to internal combustion engines, andmore particularly to a new and improved rotary engine utilizing pistonsand cylinders in a fuel-injected, two-stroke cycle, in which the pistonsare stationary and the cylinders revolve to turn the drive shaft. Theengine of the present invention is equally well adapted for operation asa spark-ignition engine, or as a compression-ignition engine, andtherefore can run on volatile liquid fuels, such as gasoline, butane,propane, or the like, or on fuels of lower volatility, such as kerosene,Diesel fuels, and the like.

One of the disadvantages of prior internal combustion engines is thelarge number of moving parts involved, which are expensive tomanufacture and assemble, have large frictional losses that subtractfrom the net power output of the engine, contribute to vibration andnoise, and wear out. Reciprocating parts such as pistons and connectingrods consume power to accelerate them from a standstill up to maximumvelocity, and then slow them back down to a standstill again.

Another disadvantage of prior piston-driven engines is that they haveabout reached the peak of performance development from the standpoint ofpower per cubic inch displacement, and power per pound of engine weight.For unsupercharged high performance engines, used in non-racingautomobiles and the like, the maximum power output ranges from about0.50 to about 0.80 h.p. per cubic inch displacement, with engine weightsranging from 3 to 4 lbs. per horsepower. Highly developed racing engineshave considerably better performance than this, but the cost isextremely high. Two-stroke cycle engines used in outboard motors andmotorcycles also have high power-per-cubicinch and lowweight-per-horsepower ratios, but at a cost of extremely high specificfuel consumption due to their wasteful discharge of large volumes ofunburned fuel into the atmosphere, which makes them seriouslyobjectionable because of atmospheric pollution.

SUMMARY OF THE INVENTION The primary object of the present invention isto provide a new and improved internal combustion engine of thetwo-stroke cycle, piston-and-cylinder type, having only three movingparts, exclusive of accessory equipment such as ignition system, fuelinjection pump, starting motor, electrical generators, and cooling airblowers.

Another important object of the invention is to provide an engine of theclass described in which there are no reciprocating parts, but onlyrotating parts.

Another object of the invention is to provide a fuelinjected internalcombustion engine of high thermal efficiency due to good scavenging ofthe cylinders and to good turbulence of the air within the cylinder atthe moment of fuel injection.

Thermal efficiency is further promoted by the high operating temperatureof the engine, which results in more complete combustion of the fuel.Another advantage of the engine is that the hot exhaust gases are mixedwith fresh air immediately upon leaving the cylinders, and this aids inoxidizing any unburned fuel in the exhaust, thereby reducing atmosphericpollution to an extremely low level.

A further object of the invention is to provide an intemal combustionengine having an extremely high power-to-weight ratio, and also a highpower-percubic-inch ratio.

Still a further object of the invention is to provide an internalcombustion engine of the class described, which is relativelylightweight, simple and inexpensive to manufacture, vibrationless andvirtually trouble free.

The above objects are achieved by providing an engine in which pairs ofpistons are fixedly mounted on opposite sides of a hollow stationaryshaft, and an assemblage of radially arranged cylinders rotates about aneccentric crank pin on a rotary drive shaft. The rotary drive shaft andstationary shaft are axially aligned, and the cylinder assemblage orbitsaround the common axis of the shafts, while at the same time rotatingabout the crank pin. A central gear fixed to the stationary shaft mesheswith a ring gear on the cylinder assembly, to synchronize the rotationaland orbital movements of the assemblage so that the pistons aresuccessively withdrawn from one cylinder and inserted into the oppositecylinder, spaced from the first. There are twice as many cylinders aspistons, and each piston leaves its respective cylinder at the end ofthe power stroke, and enters the opposite cylinder at the beginning ofthe compression stroke. Fuel is injected into the combustion chambersthrough nozzles in the outer ends of the pistons as each piston reachesthe end of its compression stroke. The engine may be operated on eitherthe Otto cycle or the Diesel cycle. If operated on the Otto cycle, sparkplugs may be mounted in the outer ends of the stationary pistons.Ignition wires and fuel lines pass through the hollow center of thestationary shaft to external housing of the engine, where they areconnected to their respective accessory units.

Among the advantages inherent in the abovedescribed construction are thefollowing: (1) there is no reciprocating or oscillating movement in theengine all motion is pure rotational; (2) there are only threemoving-parts, consisting of cylinder block, drive shaft, and a small,free-turning pinion gear; (3) the pistons do not touch the cylinderwalls and therefore do not need lubrication, hence the engine can runmuch hotter than conventional engines; (4) any blow-by may be burned inan afterburner to reduce unburned fuel in the tailpipe emissions to anabsolute minimum; (5) the fine tolerances and balance required by highspeed are easily achieved because of the all-rotary motion of theengine; (6) the cost of close-tolerance machining and precision bearingsis offset by the simplicity of construction no valves, valve springs,cam shaft, timing gears, connecting rods, etc.; (7) the cylinders areaircooled and light in weight; (8) air for supercharging also cools thepistons and scavenges the cylinders; (9) any number of cylinders can beturned around one crank-plate; 10) the engine is extremely compact, andhas a high power output per cubic inch of displacement; (1]) it has thesmoothness and high RPM of a turbine, with the high torque of a pistonengine; (12) it is reversible, and will run equally well in eitherdirection; and (13) almost any fuel can be used.

Other objects and advantages of the invention will become apparent tothose skilled in the art from the following detailed description of thepreferred embodiment thereof, with reference to the accompanyingdrawings.

v 3 BRIEF DESCRIPTION OF THE DRAWINGS:

- FIG. 1 is a sectional view through an engine embodying the principlesofthe invention; v

FIG. 2 is a reduced-scale sectional view through the same, taken at 2,-2in FIG. 1, showing the relative positions of the cylinders, pistons, andcounterweight for an initial position of the drive shaft;

. FIG. 3 is a view similar to FIG. 2, in which the drive shaft (andattached counterweight) have been rotated 90 in the clockwise direction,while the cylinders have been rotated 45? in the same direction;

FIG. 4 shows the drive shaft and counterweight rotated another 90 in theclockwise direction from the I positionshown in FIG. 3, while thecylinders have been rotated another 45";

FIG. 5 shows the drive shaft and counterweight rotated another 90 fromthe position shown in FIG. 4, with the cylinders rotated another 45; IFIG. 6 shows the engineafter one complete revolution of the drive shaftand counterweight; and

FIG. 7 is a sectional view taken at 7-'-7 in FIG. .1, showing the geararrangement for synchronizing the rotation of the cylinders with theirorbital movement 'aroundthe drive shaft.

' DESCRIPTION or THE PREFERRED EMBODIMENT;

ln'the drawings, the reference numeral 10 designates the engine in itsentirety. The engine is shown with its drive shaft perpendicular,-butthis is not essential, as the engine will operate equally well in anyposition. The

. operating mechanism is enclosed within a stationary housing 12consisting of circular end walls 14 and 16, and a cylindrical outer wall18 connecting the end walls. "Projecting through the center of the top'end wall 16 (as seen in FIG. 1) andfixedly secured thereto, is astationary hollow shaft 20. Axially aligned with shaft 20 onthe,opposite side of the housing is a rotatable drive shaft 22, which isjoumaled in a bearing 24in the hous-- gear on the side diametricallyacross from pinion 62 is a larger diameter gear 66, which is fixedlymounted on chaft 20. The purpose of pinion "'62 is to press the cylinderblock 36 in the direction to hold the ring gear 64 in mesh withstationary gear 66 as the cylinder block orbits around the latter-. I I

The pitch diameter of gear 66 isexactly one-half the pitch diameter ofring gear 64, which means that gear 66 has half as many teeth as gear64, and therefore one orbital revolutionof the cylinder block 36 aboutthe stationary shaft 20 causes the cylinder block to rotate a halfrevolution about .the'crank pin 30. The purpose of.

- this synchronized movement will becomc apparent as the descriptionproceeds. I

Formed in the top side of the cylinder block is a central circularaperture 68, through which jets of air are directed from conduits 70.The conduits are connected to an external, engine-driven blower 72. Onthe bottom side of the cylinder block is a plurality of exhaustapertures 74 arranged in a circle concentric with crank pin 30. Thehousing 12 also has a plurality of exhaust outlets 76 arranged in acircle concentric with the drive shaft, and these are located so that asthe cylinders orbit around the drive shaft and rotate about the crankpin 30, the apertures 74 pass in front'of the outlets 76, allowing theair from conduits 70, mixed with exhaust gases from the cylinders, to bedischarged from the housing. Outlets 76 would, of course, be connectedvto a suitable manifold, not shown, and be carriedthence to a muffler.Alternatively, the exhaust outlets 76 may be connected to an afterburner(not shown) where any unburned fuel remaining in the exhaust gases isoxidized. The fully oxidized exhaust gases leaving the af terbumer couldbe utilized to drive a turbine (not shown) which could serve as themotive power for blower 72.

Disposed within the cylinder block 36 are stationary pistons 78 and 80,which are mounted on opposite sides of stationary shaft 20. Pistons 78and 80 are herein shown as hollow, spherical bodies whose outsidediameter is only a few thousandths of aninchless than the insidediameter of the cylinders,so that the pistons are an extremely close fitwithinthe cylinders. Close fit is necessary because there are nocompression or oil scraper rings, as in conventional engines. It is notessential that the pistons 78, '80 be spherical, and that the respect todrive shaft 22, 26, is a crank pin 30, which is connected to the shaftby crank arms 32 and 34.

Within the housing 12 is a cylinder block 36 consist 1 ing of anassemblage of four individual cylinders 38, 40,

' one. Arm 52 has a bearing 56 which is joumaled on stationary shaft 20.Arm 52 also has an extension arm 58 extending radially away from shaft20, and joumaled in a bearing 60 in the outeruend of arm 58 isafreerunning pinion 62: Pinion 6 2 meshes with a ring gear 64 that ispressed into a suitable seat formed in the top side of the'cylinderblock 36, and also meshing with-the ring cylinders be circular incross-section, as shown in the drawings, instead, the pistons mightbemade in the form of cylinders having their axes parallel to the axisof the drive shaft, and with their length and diameters approximatelyequal, in which case the cylinders 38, 40, 42, 44 would be square incross-section. Other configurations of pistons and cylinders could beused, but

minimize combustion blow-by. The use of piston rings is not feasiblebecause of the rolling action of the pistons within the cylinders. Thereis no physical contact between the pistons andcylinders,and therefore nolubricating oil is required within the cylinder block,

although the bearings 24, 45, 56 and 60 are supplied with lubricant inthe usual manner.

Centering of the pistons within their respective cylinders isaccomplished by two means: (l precision gears 64, 66, which accuratelysynchronize the rotation of cylinder block 36 with its orbital movementabout the axis 20, 22; and (2) turbulence of the air within the cylinderas the piston moves upwardly therein, which causes an equalized pressureto be exerted against the piston from all sides, causing the piston tocenter itself with respect to the cylinder.

Combustion blow-by may be further minimized by serrating either thepistons of the cylinders, or both, to provide roughened surfaces whichcreate extremely high frictional resistance to the high velocity flow ofcombustion gases between them.

Projecting inwardly toward the shaft from the outer end of each pistonis a protuberance 82, which has bored and tapped holes provided thereinto receive a spark plug 84 and two fuel injector nozzles 86. The fuelinjector nozzles have fuel lines 88 connected thereto, which passthrough the hollow center of shaft 20 and are connected to asolid-state, electronic fuel injection pump 90, of the type currentlyused on the Volkswagen automobile engine. Ignition wires 92 areconnected to the spark plugs 84, and these also pass through the hollowcenter of shaft 20, to an ignition system 94, which may be aconventional breaker-points type of system, or any of the solid-stateelectronic systems which are also available at this time. Spark plugs 84are somewhat unconventional in the respect that they are screwed intothe pistons from the outer ends of the latter, and the points of thespark plug are also exposed to the outer ends of the pistons. Theterminal at the other end of the spark plug makes contact with aspring-loaded contact point 95 at the bottom of the cavity into whichthe spark plug is screwed, and contact point 95 is connected to theignition wire 92.

The hollow center of stationary shaft 20 is also connected at 97 toblower 72 so that air from the latter is blown into each of the pistons78, 80 to cool them. Outwardly directed, collar-shaped baffles 96 on theinner end of shaft 20 send the stream of cooling air into the hollowcenter of each of the pistons, where it circulates around and finallyexits through discharge apertures 98 in the sides of the piston adjacentthe point of connection to the shaft. This placement of the dischargeapertures 98 causes the air leaving the pistons to be directed up intothe cylinders as the pistons enter their respective cylinders, therebyscavenging any remaining exhaust gas and aiding in cooling thecylinders. The discharge apertures 98 are spaced angularly around thebase of each piston and face toward the axis of the shaft 20, 22. Theapertures are located about degrees in from a plane passing through thecenter of the piston perpendicular to an axis extending through thecenters of both pistons. Thus, the discharge apertures 98 are located onthe pistons 78, 80 so that as the piston first approaches a cylinder,the jet of air issuing from the aperture 98 on one side of the pistonblows upwardly into the cylinder head 46 and down on the other side ofthe cylinder, as shown by the arrows in FIGS. 2-6, thereby scavengingany exhaust gases that may remain in the cylinder from the previouspower stroke. As the cylinder block continues to rotate and orbit, thepiston moves further up into the cylinder until at about the point shownin FIGS. 3 and 5, the escape of air from the cylinder is blocked by thepiston, and a slight amount of supercharging takes place before thecylinder has rotated around the block to the aperture 98 and preventsany further discharge of air therefrom.

The mode of operation of the engine is as follows: Assume first that theengine is in the condition shown in FIG. 2. Piston 78 is at the top ofcylinder 38, and the air that was trapped in the cylinder when thepiston entered the cylinder and began the compression stroke iscompressed to its maximum pressure. At this moment (or slightly before),fuel is injected through the nozzles 86 into the combustion chamber, andat the proper instant of time, the spark plug 84 is fired, causing thefuel charge to ignite. The arrows show the paths followed by the jets ofair issuing from exit apertures 98.

In FIG. 3, cylinder 38 has just about completed its power stroke, andpiston 80 has entered the bottom of cylinder 40. At this point, piston80 has just closed the bottom end of the cylinder, and air trappedbetween piston 80 and cylinder head 46 is about to be compressed ascylinder 40 starts the beginning of its compression stroke. Piston 78 isjust about to leave the bottom end of cylinder 38. It will be noted that(in FIG. 3) the flywheel 48 has advanced in the clockwise direction fromits position in FIG. 2, whereas the cylinder block 36 has rotated only45 in the clockwise direction. During the angular movement of thecylinder block 36 relative to the pistons 78, 80 in advancing from theposition shown in FIG. 2 to that shown in FIG. 3, the jets of airissuing from apertures 98 in piston 80 have scoured cylinder 40 of anyremaining exhaust gases, and in FIG. 3, the air leaving apertures 98 onone side of the piston is starting to supercharge the cylinder 40.However, the degree of supercharging is relatively small, especially athigh engine speeds.

In FIG. 4, piston 78 has been withdrawn entirely from cylinder 38, andthe combustion gases in cylinder 38 have been discharged into theinterior of the cylinder block 36, from which they escape throughapertures 74 and 76. Piston 80 is now at the top of cylinder 40, atwhich point fuel is injected into the combustion chamber and spark plug84 fires to ignite the charge. The counterweight 48 and attached driveshaft 22 have advanced clockwise another 90 from the position shown inFIG. 3, and cylinder block 36 has advanced another 45. Jets of airissuing from exit apertures 98 in piston 78 blow lengthwise intocylinders 38 and 42, acting to scavenge exhaust gases from thesecylinders.

In FIG. 5, piston 78 has entered the bottom of cylinder 42 to begin itscompression stroke in that cylinder, while piston 80 moves downward fromhead 46 of cylinder 40 on the power stroke. counterweight 48 and driveshaft 22 have advanced clockwise another 90 from the position shown inFIG. 4, while cylinder block 36 has advanced 45.

In FIG. 6, the counterweight 48 and drive shaft 22 have completed onefull revolution from the position shown in FIG. 2, while cylinder block36 has completed a half-revolution. Piston 78 is now at the top ofcylinder 42, having completed it compression stroke and being about tostart its power stroke. Jets of air issuing from apertures 98 in piston80 blow into cylinders 40 and 44 to scavenge exhaust gases from them.

sarily beconsiderably higher than in the spark-ignition engine. The fuelinjected through nozzles 86 would be of the type suitable for Dieselengines, and the timing of fuel injection would be in accordance withaccepted practice.

As mentioned earlier, the exhaust'ports 76 could be connected by amanifold to an efterburner (not shown) where additional fuel might beinjectedand burned to completely oxidize any unburned fuel remaining inthe exhaust gases. The exhaust from the afterbumer could then bedirected against a turbine (not shown) to drive the latter, and thesaidturbine could be connected by suitable gearing to the drive shaft.22 to provide additional power to the latter, or the turbine could beused to drive the blower 72.

While we have shown and described in considerable detail what we believeto be the preferred embodiment of the invention, it will be understoodby those skilled in the art that theinvention is not limited to suchdetails but might take various other forms.

We claim? s 1. An internal combustion engine comprising:

a stationary assemblageof n pistons;

an assemblage of Zn cylinders spaced equidistantly from one another in aradial arrangement;

a rotatable drive shaft having its axis of rotation concentric with thecenter of said assemblage of pistons, said drive shaft having aneccentric crank said cylinder assemblage being journaled for rotationabout said crank pin and being supported for orbital movement about theaxis of said drive shaft;

means for synchronizing the rotation of said cylinder assemblage withthe orbital movement thereof,

whereby said cylinder assemblage rotates at onehalf the angular velocityof the orbital movement thereof, said orbital movement and said rotationbeing in the same direction; means for supplying air to the interior ofsaid cylinder. assemblage and for exhausting combustion gases therefrom;each of said pistons being operable to enter one of two diametricallyopposed cylinders with which it is associated, and to move relativelylengthwise therein toward thehead of said one cylinder, thereby.compressing the air contained within the cylinder;

means for injecting fuel into the compressed air when said piston .is atthe top of its compression stroke, said fuel and air being ignited toinitiate a power stroke, during which the piston moves relativelydownwardly toward the bottom of said one cylinder;

said piston moving relatively out of said one cylinder and entering thecylinder diametrically across therefrom as said cylinder assemblagecontinues its rotational and orbital movement; and

means for cooling said piston.

2. An internal combustion engine as in claim 1, in which said pistonassemblage is mounted on a stationary shaft coaxial with saiddrive'shaft, and said fuel injection means comprises injector no'zzlesmounted on the outer ends of said pistons, each of said injectornozzles being connected to a source of fuelunder pressure by a fuel lineextendin alon said stationary shaft. An mterna com ustion engine as Incla m, 1,

which is further provided with spark plugs mounted in thef'outer ends ofsaid pistons, said spark plugs being connected byignition wiresto'an'electrical system for producing a timed spark at each plug whenits associated piston is at the top'of its compression stroke,

said ignition wires passing along said stationary shaft.

4. An internal combustion engine asin claim 1, wherein said means forsynchronizing the rotation of said cylinder assemblage with the orbitalmovement thereof comprises a stationary gear having its center locatedon the axis of said stationary shaft, and a ring gear fixed to saidcylinder assemblage and rotating said cylinder assemblage, said enginehaving discharge openings through which combustion gases are exhausted.T

6. An internal combustion engine as in claim l, wherein said pistons arehollow, and means is provided for circulating coolant fluid through saidhollow pistons. I I

7. An internal combustion engine as in claim. 5, wherein said pistonassemblage is mounted on a hollow stationary shaft coaxial with saiddrive shaft, the interior of said hollow shaft being connected by aconduit to said blower, said pistons also being hollow, and the interiorof the pistons being open to said hollow shaft, whereby cooling airdischarged by said blower is circulated through said hollow pistons tocool the same.

8. An internal combustion engine asin claim 7, wherein said pistons haveexit apertures. provided in the sides thereof, through which saidcooling air is discharged in jets directed so as to blow up into thecylinders associated with that piston prior to entering. the same so asto scavenge any combustion gases remaining in the cylinder.

9. An internal combustion engine as in claim 7,

wherein said pistons have fuel injectors and spark plugs mounted in theouter ends thereof, said fuel injectors being connected by fuel lines toa source of fuel under pressure, said spark plugs being connected byignition wires to an electrical system for producing a timed spark ateach plug when its associated piston is at the top of its compressionstroke, said ignition wires and said fuel lines passing through saidhollow stationary shaft,

10. An internal combustion engineas in claim 1, in which there is acounterweight connected to said drive shaft to rotate therewith, saidcounterweight extending in the opposite direction from said crankpin andbeing shaped and proportioned to allow said cylinder assemblage to turnfreely about the crankpin as it orbits about the axis of said driveshaft, said counterweight counterbalancing the mass of said cylinderassemblage which is centered on said crankpin.

1. An internal combustion engine comprising: a stationary assemblage ofn pistons; an assemblage of 2n cylinders spaced equidistantly from oneanother in a radial arrangement; a rotatable drive shaft having its axisof rotation concentric with the center of said assemblage of pistons,said drive shaft having an eccentric crank pin; said cylinder assemblagebeing journaled for rotation about said crank pin and being supportedfor orbital movement about the axis of said drive shaft; means forsynchronizing thE rotation of said cylinder assemblage with the orbitalmovement thereof, whereby said cylinder assemblage rotates at one-halfthe angular velocity of the orbital movement thereof, said orbitalmovement and said rotation being in the same direction; means forsupplying air to the interior of said cylinder assemblage and forexhausting combustion gases therefrom; each of said pistons beingoperable to enter one of two diametrically opposed cylinders with whichit is associated, and to move relatively lengthwise therein toward thehead of said one cylinder, thereby compressing the air contained withinthe cylinder; means for injecting fuel into the compressed air when saidpiston is at the top of its compression stroke, said fuel and air beingignited to initiate a power stroke, during which the piston movesrelatively downwardly toward the bottom of said one cylinder; saidpiston moving relatively out of said one cylinder and entering thecylinder diametrically across therefrom as said cylinder assemblagecontinues its rotational and orbital movement; and means for coolingsaid piston.
 2. An internal combustion engine as in claim 1, in whichsaid piston assemblage is mounted on a stationary shaft coaxial withsaid drive shaft, and said fuel injection means comprises injectornozzles mounted on the outer ends of said pistons, each of said injectornozzles being connected to a source of fuel under pressure by a fuelline extending along said stationary shaft.
 3. An internal combustionengine as in claim 1, which is further provided with spark plugs mountedin the outer ends of said pistons, said spark plugs being connected byignition wires to an electrical system for producing a timed spark ateach plug when its associated piston is at the top of its compressionstroke, said ignition wires passing along said stationary shaft.
 4. Aninternal combustion engine as in claim 1, wherein said means forsynchronizing the rotation of said cylinder assemblage with the orbitalmovement thereof comprises a stationary gear having its center locatedon the axis of said stationary shaft, and a ring gear fixed to saidcylinder assemblage and rotating therewith, said ring gear meshing withsaid stationary gear and having a pitch diameter equal to twice thepitch diameter of said stationary gear.
 5. An internal combustion engineas in claim 1, wherein said means for supplying air to the interior ofsaid cylinder assemblage and for exhausting combustion gases therefromcomprises a blower having conduits carrying air into the interior of theengine and blowing air transversely through the central portion of saidcylinder assemblage, said engine having discharge openings through whichcombustion gases are exhausted.
 6. An internal combustion engine as inclaim 1, wherein said pistons are hollow, and means is provided forcirculating coolant fluid through said hollow pistons.
 7. An internalcombustion engine as in claim 5, wherein said piston assemblage ismounted on a hollow stationary shaft coaxial with said drive shaft, theinterior of said hollow shaft being connected by a conduit to saidblower, said pistons also being hollow, and the interior of the pistonsbeing open to said hollow shaft, whereby cooling air discharged by saidblower is circulated through said hollow pistons to cool the same.
 8. Aninternal combustion engine as in claim 7, wherein said pistons have exitapertures provided in the sides thereof, through which said cooling airis discharged in jets directed so as to blow up into the cylindersassociated with that piston prior to entering the same so as to scavengeany combustion gases remaining in the cylinder.
 9. An internalcombustion engine as in claim 7, wherein said pistons have fuelinjectors and spark plugs mounted in the outer ends thereof, said fuelinjectors being connected by fuel lines to a source of fuel underpressure, said spark plugs being connected by ignition wires to anelectrical system for producing a timed spark at each plug when itsassociated piston is at the top of its compression stroke, said ignitionwires and said fuel lines passing through said hollow stationary shaft,10. An internal combustion engine as in claim 1, in which there is acounterweight connected to said drive shaft to rotate therewith, saidcounterweight extending in the opposite direction from said crankpin andbeing shaped and proportioned to allow said cylinder assemblage to turnfreely about the crankpin as it orbits about the axis of said driveshaft, said counterweight counterbalancing the mass of said cylinderassemblage which is centered on said crankpin.